Arsenal survived a major scare to reach the Europa League last 16, beating Ostersunds 4-2 on aggregate despite a 2-1 loss on Thursday.
Arsene Wenger's side conceded twice within 70 seconds in the first half at the Emirates Stadium and managed only a solitary Sead Kolasinac strike in return, although their 3-0 first-leg win was enough to see them through.
Borussia Dortmund battled past Atalanta in Bergamo to reach the next round, while Atletico Madrid and AC Milan picked up 1-0 wins to ease through comfortably.
There were tragic scenes in Bilbao, though, where a police officer died following clashes between fans ahead of the meeting between Athletic Bilbao and Spartak Moscow.
Complacent Arsenal survive, Celtic crash out
A Calum Chambers own goal and a fine strike from Ken Sema gave Ostersunds a 2-0 half-time lead over Arsenal, leaving the Gunners fearing a spectacular collapse.
Kolasinac's strike just after the break eased some of the anxiety around the Emirates, but Arsene Wenger will have been concerned by the complacent performance, while Ostersunds celebrated a famous win.
Celtic took a 1-0 lead into their second leg with Zenit but offered meek resistance against the Russians, who ran out 3-0 winners to advance 3-1 on aggregate.
Branislav Ivanovic, Daler Kuzyaev and Aleksandr Kokorin got the goals for Roberto Mancini's side.
6 - Graham Potter is just the sixth English manager to win at the Emirates in all competitions after (Alan Curbishley, Phil Brown, Harry Redknapp, Michael Appleton and Garry Monk), but the first to do so in European competition. Future. pic.twitter.com/mUFkE5RVBG— OptaJoe (@OptaJoe) February 22, 2018
Atletico advance, Bilbao win soured by violence
Atletico made light work of their second leg against FC Copenhagen, with Kevin Gameiro's fine strike securing a 1-0 win on the night and a 5-1 triumph on aggregate.
Bilbao lost 2-1 to Spartak Moscow but still advanced 4-3, although their success was marred by violent clashes between fans before kick-off, which saw a police officer involved in attempts to restore order die after suffering a heart attack.
Basque rivals Real Sociedad crashed out with a 4-3 aggregate loss to Red Bull Salzburg, who won 2-1 in Austria thanks to Valon Berisha's second-half penalty.
Meanwhile, a number of Marseille fans missed kick-off due to problems at Braga's stadium, but the Ligue 1 side's 1-0 defeat did not stop them going through 3-1 on aggregate.
Dortmund battle through, AC Milan make it look easy
Dortmund were staring at an away-goals defeat to Atalanta until Marcel Schmelzer struck seven minutes from time in Bergamo, thereby securing a 1-1 draw and 4-3 aggregate triumph.
There was an unsavoury incident involving Michy Batshuayi, though, who took to social media to accuse some home fans of racist abuse after the match.
Milan made light work of Ludogorets, with Fabio Borini's effort sealing a 1-0 second-leg win and 4-0 aggregate success, ensuring a second Serie A presence in the last 16.
|Lehmann slams ´disgraceful´ Newlands abuse|
|Di Maria predicts ´big change´ at PSG after Champions League failure|
|Everton defender Holgate warned for alleged homophobic tweets|
|Russia 0 Brazil 3: Coutinho on target in routine win|
|Icardi must keep performing to earn Argentina recall, says Zanetti|
|Different place, same Zlatan - Ibrahimovic determined to maintain winning DNA with LA Galaxy|
|Injured Cavendish out of Commonwealth Games|
|Experience the key for Juventus in title race, insists Trezeguet|
|Stanikzai plays through the pain to guide Afghanistan to glory|
|Lyon and Paine frustrate Proteas after Morkel joins 300 club|
|Messi lacks Maradona´s charisma, claims Batistuta|
|Usain Bolt claims he´ll return to Dortmund|
|Trezeguet confident Pogba will shine at the World Cup|
|Ibrahimovic departs Europe with remarkable haul of league titles|
|´Very, very happy´ Lanzini loves West Ham amid transfer talk|
|LA Galaxy confirm Ibrahimovic arrival|
|Pressure off soaring Falcons, says Flood|
|Afghanistan edge out Ireland to secure World Cup spot|
|Age no barrier to Messi brilliance - Kluivert|
|Japan 1 Mali 1: Late Nakajima strike earns a draw|
|Record-breaking Stockdale named Six Nations´ top player|
|Warner in verbal altercation with fan following dismissal|
|Uruguay 2 Czech Republic 0: Suarez scores 50th international goal|
|I choose the Galaxy! - Ibrahimovic confirms LA switch|
|Retiring Morkel joins the 300 club|
|Parker accuses Joshua of disrespect towards NZ media|
|Roberto Carlos declares Neymar and Brazil the World Cup favourites|
|Kluivert tells son Justin to snub Manchester United for Barcelona|
|It´s hard to swing it when it´s not round - Anderson unhappy with pink ball|
|Reading appoint former Swansea boss Clement|
|I had to get out of my comfort zone - Goretzka explains Bayern switch|
|Isaako kicks Broncos to golden-point win over Tigers|
|Adelaide United 5 Newcastle Jets 2: Five-star Reds end winless streak|
|Crusaders back to winning ways as Rebels rout Sharks|
|Goals, nutmegs and cheers - Usain Bolt impresses in Borussia Dortmund training|
|Ricciardo given three-place grid penalty|
|Williamson frustrated not to kick on after record-breaking century|
|De Bruyne: Don´t compare me to Messi and Ronaldo|
|Raza apologises for Zimbabwe´s World Cup woe|
|Real Madrid can win the Champions League, Roberto Carlos claims|
|Martinez determined to earn World Cup place|
|Horner and Arrivabene clash over Ferrari´s recruitment from FIA|
|Williamson notches record ton but rain frustrates New Zealand|
|Arthur ´counting the days´ to Barcelona switch|
|English football must address racism, says Southgate|
|Alisson can be world´s best – Taffarel|
|Rockets need OT to beat Pistons, Hornets record sixth biggest win|
|Hamilton contract to be finalised ´soon´, says Wolff|
|Warriors star Curry ´definitely´ wants ownership stake in Panthers|
|Kings´ Kopitar tallies first four-goal game|
|Ter Stegen dismisses ´Messi with gloves´ label|
|Medvedev fumes after win, Shapovalov battles through|
|Buffon: Messi more complete than Ronaldo|
|Neymar is irreplaceable, says Tite|
|Halep joined by Pliskova and Kerber on mixed day for seeds in Miami|
|Rahm joins Johnson in early elimination, McIlroy hits back|
|Red Wings´ Green to undergo cervical spine surgery|
|Conti: Milan much better thanks to Gattuso|
|Show must go on in Hollywood! - Pogba and Mkhitaryan say Ibrahimovic goodbyes|
|Arthur: I´ll find out if Messi is from this planet|
|Barcelona better than Real Madrid even if Neymar signs - Iniesta|
|I haven´t booked a holiday yet - Leno hoping for World Cup call|
|I may be 40 but I´m still Juve´s number one – Buffon bullish over Italy return|
|Italy coach Di Biagio dismisses Raiola rage over Balotelli snub|
|Lopetegui not ruling out Martinez World Cup chances|
|Late Widnes rally sees off Salford|
|Ailing Halep battles past Dodin in Miami|
|Spain defender Ramos targeting Casillas caps record|
|Pogba gets no special treatment from Deschamps|
|Defending champion Johnson dumped out of WGC Dell Match Play|